Thread-cutting apparatus



H. KAYFETZ 2,389,857

THREAD- CUTTING APPARATUS Nov. 21, 1 945.

2 Sheets-Sheet 1 Filed June 3, 1944 W Illllllllllllllllllllllllllllllllllllllllll Nov. 27, 1945- KAYFETZ 2,389,857

THREAD- CUTTING APPARATUS Filed June 3, 1944 2 Sheets-Sheet 2 INVENTOR fla/rwyflayi 72 i BY V oRNEY Patented Nov. 27, 1945 THREAD-CUTTING APPARATUS Harry Kay-fetz, Newark, N}, J.

Application June 3, 1944, Serial No. 538,579

4 Claims.

This invention relates in general to threadcutting apparatus of the type comprising threadcutters such as dies or chasers, a holder or stock therefor and means for rotating, said holder or stock.

A prime object of my inventionv is to provide a novel and improved construction andcombination of thread cutters, a holder therefor and power operated means for rotating. said holder, such that threads can be cut, easily and rapidly and with a minimum of' efiort on the part of the operator.

Further objects are to provide in apparatus of the character described a holder for thread-cutters or dies which shall embody novel and improved means for applying power thereto from a convenient source of power such as. a chain hoist or an electric motor whereby the operator of the apparatus shall be relieved of the labor incident to hand operation of the apparatus and threads can be out many times more rapidly than by hand operation; and to provide such a threadcutting apparatus that can be easily and. quickly connected and disconnected to and from the power drive, respectively, and can be operated conveniently by hand when desired.

Other objects are to provide a novel and improved simple and inexpensive construction and combination of a die block and a holder therefor; and to obtain other advantages and results. that will be brought out by the following description in conjunction with the accompanying drawings in which Figure 1 is a front elevational view of a thread cutting apparatus embodying my invention.

Figure 2 is a side elevational view thereof,

Figure 3 is a view similar to Figure 1, showing a modification of the invention.

Figure 4 is an enlarged vertical longitudinal sectional view on the line 4-4 of Figure 1.

Figure 5 is a transverse vertical sectional view taken on the line 5--5 of Figure 4.

Figure 6 is a front elevational view of another form of the invention.

Figure 7 is a vertical longitudinal sectional view on the line 'l-1 of Figure 6.

Figure 8 is a view similar to Figure 6 showing another form of the invention, and

Figure 9 is a vertical longitudinal sectional view on the line 9-9 of Figure 8.

Specifically describing the embodiment of the invention illustrated in Figures 1 to 5 inclusive, my thread cutting apparatus includes a die holder 5 which has a central opening 2 therethrough and has a thread cutting die 3 secured in the holder at one end of said opening. The outer periphery of the holder is in the iorm. of a power transmitting element, preferably a pulley which has a circumferential groove 4., to cooperate with another power transmitting element, such as. a flexible cable 5 as shown in Figures 1, 2 and 4, or a driving belt 6 as shown in Figure 3.

Preferably the die 3 is a solid or block die of a generally known type which includes the usual lands 6a in which are formed the thread cutters 1. One side of the holder or pulley has a recess or seat 8 in which the die block 3 is mounted, and suitable fastening elements such as cap screws 9. are provided for fastening the die block in said seat.

The die block is coaxial with the opening 2 through the holder and with this construction, it will be observed that the end of a pipe In to be threaded may be inserted through the opening 2. into engagement with the thread cutters I and held against rotation in any suitable manner as by a vise H on a bench l2, whereafter upon rotation of the holder I, a thread will be cut in the pipe as indicated at [3.

In some cases it is desirable to provide a lead screw for the die, and accordingly the holder I may have anexteriorly threaded tubular extension l4 coaxial with the hole 2 and at the side of the holder opposite the die, to cooperate with an interiorly screw threaded sleeve l6 which may be rigidly clamped on the pipe H) by set screws H.

In accordance with the invention, power is applied tothe holder l, and as shown in Figures 1, 2 and 4, the application Of power takes place through the cable 5 which is wound on the pulley with one end free and to be separably connected to the load hook l8 of a known type of hoisting mechanism H) which will exert a pulling force on the cable and consequentl will rotate the die holder l as the cable is unwound from the pulley groove in the dieholder. This construction makes possible the rapid rotation of the die holder and consequent cutting of the die thread rapidly and with a minimum of efiort on the part of the operator, the hoist I9 being easy to operate manually and afiording great power for rotating the die easily and quickly connected to and disconnected from the belt 6. I

If desired, one side Of the die holder may have one or more sockets 24 to receive handles for hand operation of the apparatus.

In Figures 6 and 7 is shown a modification of the invention wherein the die holder 26 is in the form of a tube and has the die block 21 mounted in one end thereof in a manner similar to that in which the die block 3 is mounted in the die holder I. Said end of the die holder also has a circumferential flange 28 on which are ratchet teeth 29 that cooperate with a reversible pawl or dog 30 which is mounted in a collar 3| that is rotatable on the die holder 26. As shown, the collar has a recess 32 in one side thereof, the bottom of which' abuts one side of the flange 28, and a-ring 33 is secured to the collar in abutting relation to the other side of said flange to hold the collar against longitudinal movement on the die holder. The pawl 30 is normally pressed by a spring 34 into engagement with the ratchet teeth 29 and may be positioned to rotate the die holder in either direction upon rotation of the collar 3|.

Figure 6 shows the pawl in the position to rotate the die holder in the direction of the arrow and by pulling upwardly on the finger piece 35 which is connected to the pawl, and then rotating the pawl, the latter will be positioned to rotate the die holder in the opposite direction.

In accordance with the invention, the collar 3| also has a power transmitting element which is shown in the form of a grooved pulley 36 and may cooperate with the other power transmitting elements in the same manner as the pulley of the die holder I hereinbefore described. To permit hand operation of the die holder, the collar 3| may have one or more handle sockets 31 in each to removably receive a handle 38.

Figures 8 and 9 show another modification of the invention wherein the die holder 40 has a plurality of circumferentially spaced sockets 4| each to removably receive a die chaser 42 in known manner. The die chasers are fitted into the sockets from the inner ends thereof and are held in position by spring influenced pins 43 mounted on the die holder and normally seated in sockets 44 in the corresponding die chasers. The die holder has an exteriorly threaded tubular extension 45 which cooperates with an interiorly screw t,hread ed sleeve 46 that may be rigidly clamped by set screws 4! on a pipe 48 to be threaded. The threads on the extension 45 and the sleeve 46 thu provide a lead screw. A collar 49 is rotatably mounted on the sleeve 46 and is held against longitudinal movement thereon. This collar has rigidly projecting from one end thereof a plurality of pins 50 each of which is loosely slidably received in an opening in the die holder 40.

In accordance with the invention a power transmitting element such as a grooved pulley ill 52 is mounted on said pins 50 to move longitudinally thereof but to be non-rotatable relatively thereto. As shown, the pulley has a central web portion 53 in which are holes 54 through each of which loosely passes one of the pins 50. The pulley 52 may be driven in any suitable manner, e. g. as hereinbefore described, and when rotated will rotate the .di holder 40 which, as it rotates will slide longitudinally of the pins 5-9. The movement of the pulley longitudinally of the pins 50 permits the pulley to 'be located at the most advantageous point for the application of power to the die holder and at the same time compensates for sliding of the die holder on the pins.

While I have shown and described the invention as embodied in certain details of construction and in conjunction with different types of dies and die holders, it will be understood by those skilled in the art that the details of construction of the invention may be widely modified and the invention may be embodied in other types of die holders, all'within the spirit and scope of the invention.

What I claim is:

1. In thread-cutting apparatus, the combination of a die holder and a sleeve having a coaxial screw-threaded connection with each other, means for rigidly securing said sleeve on a pipe to be threaded, a collar rotatable on said sleeve coaxially therewith and having pins projecting from one end thereof, said die holder having a hole to freely slidably receive each said pin, and a pulley longitudinally movably mounted on said pins and non-rotatable relatively thereto.

2. Thread-cutting apparatus comprising in combination a pulley having a die mounted therein to rotate coaxially therewith, means for holding a pipe to be threaded, means for'mountlllg said die holder on said pipe for rotation relatively thereto, a cable wound circumferentially on said pulley with one end free; and means for exerting a pull on said free end of said cable.

3. Thread-cutting apparatus comprising a pulley having a circumferentially grooved rim and a web within said rim having an opening coaxial with said rim, 2. thread-cutting die block mounted on said web coaxially with said opening, an exteriorly screw-threaded sleeve screw-threaded on said extension, and means for securing said sleeve rigidly on a pipe to be threaded.

4. Thread-cutting apparatus comprising a pulley including a rim and a web within said rim having an opening coaxial with said rim, a die block, means securing said dieblock to said web coaxially with said opening, said rim being exposed for engagement with afiexible power transmitting element, and means for mounting said die block and said pulley on a pipe to b threaded for rotation relatively to said pipe.

HARRY KAYFETZ. 

